Electric motor vehicle



P 1941- J. TJAARDA 2,254,552

ELECTRIC MOTOR VEHICLE Original Filed June 13, 1958. 2 Sheets-Sheet l 7 INVENTO R BY P 1941- J. TJAARDA ELECTRIC MOTOR VEHICLE Original Filed June 13, 1938 2 Sheets-Sheet 2 4 f 4 QRRRPN INVENTOR A TTORxb Y5.

UNITED STATES PATENT OFFICE ELECTRIC MOTOR VEHICLE John Tjaarda, Detroit, Mich., assignor to Briggs Manufacturing Company, Detroit, Mich., a corporation of Michigan Original application June 13, 1938, Serial No.

213,393. Divided and this application September 21, 1939, Serial No. 295,873

8 Claims. (Cl. 172-291) This invention relates to self-propelled vehi- Fig. 3 is a sectional view taken in the direccles and more particularly to electrically driven tion of the arrows on the plane passing through vehicles. The present application is a division the broken line 3-3 of Fig.2. of my copending application Serial No. 213,393, Fig. 4 is a view similar in part to Fig. 2, the filed June 13, 1938, now Patent No. 2,208,710. 5 parts of the control device being shown in posi- One of the objects of the present invention tions resulting from the p essing down of the is to provide an improved self-propelled vehicle acceleration pedal, having a power plant capable-oi developing a g. 5 is a sectional view taken in the direcsufflciently high starting torque onthe driving tion f the a s n e section plan passed wheels without the aid of a torque increasing t rough the line 5-5 of Fig. 4. device, such as a t i i Fig. 6 is a sectional view illustrating the con- Another object of the invention is to provide Struetion of one interrupter Switch. D l y an improved electric motor vehicle operated from oflwhieh are p oyed in the control device. a storage battery, means being provided whereby Fig. 7 is an electric wiring dia am illustratthe loads on the battery are q t t was. 1'; ing the electric cir'cuits'employed in the'mot or sively on all cells thereof, causing substantially vehicle and their interrelation, uniform discharging of all of the cells. I Before explaining in d a l t o resent in- A further'object of the invention is to provide e n it is to be understood that the inve an improved self-propelled vehicle in which the tionis not limited in its applic tion to the dedisadvantages incidental to the operation of astails of construction and arrangement of parts oline engines, such as objectionable odors, smike, illustrated in the accompanying d w s, Since possibility of carbon monoxide poisoning and the e invention p e of other embodiments like, are eliminated. J and, of being practiced or carried out in various A still further object of the invention is to Ways. Also it is to be understood that the provide an improved self-propelled vehicle in 2 P seology, or te minology employed herein is which such mechanisms as a transmission, a dif- I for he P po e of d scription and not of limiferential, a propeller shaft and universal joints fl l n, and it is not intended to limit the invenare entirely eliminatei tion claimed herein beyond the requirements of A still further object of the invention is to the prior art. provide an improved self-propelled vehicle in. In e gs there is shown, by way of which the difficulties of starting and necessity example; a v l constructed in accordance of warming up the engine are eliminated. i e embodiment pf the Present invention-1 A still further object of the invention is to a T Yehlcle i Provided with e Source of elecprovide an electrically propelled vehicle .oper-/ h i 1n the P sent instance a storage ated by electric current derived from a storage batterwdlvlded into two sections and on e ectric battery adapted to be charged from time i to 4 Power P a t arranged at the rear of the vehicle ti a and operatively connected to the rear axle for It is an added object of the present invention #Mdrivmg e The c e body and its to provide an improved electric motor vehicle of ,steerihg a le arev of substant ally conthe fofegoing character, which is simple in cont n types{as 11 In connection h motor -struction, dependable in operation, is; relatively. Vghlcles- W111 de s od, however, that inexpensive ,to manufacture and is easy to pthel types of vehicle bodies and other arrangeice and remit 7 M J r ments of thefaxles, such for instance as provid- Other objects of this invention will appear in. the driving axle at the front of t c the following description and appended claim .may be p y d a advantageously used in reference being had t t acc'qmpanylng a connection with the present invention,

ings forming a part of this specification wherein' e er ng tothe drawings, and particularly to like reference characters designate corresponding g the mo r' eh cle Shown therein resemparts in t s v bls in its appearance a conventional motor ve- Fig. 1 is a side view, partly in section', ofa hide. The sections of the storage battery in motor vehicle embodying the present invention. and II are arranged under the hood of the ve- Fig 2 1s a side Viewth t pedal ope! hicle and at the rear thereof, respectively, as

ated control device, the same being shown with shown. With the present type of vehicle, the

its parts in positions before the pedal is pressed rear section II of the battery is larger than the down for acceleration. front section 10, which arrangement causes the e we ht to be carried by the driving axle, may in reasing the traction of the wheels on the road. Other suitablgeehrlregigements of the sections may also e electric motor used in the present embodiment is indicated by the numeral II. Said motor is operatively mounted on the vehicle structure and preferably consists of two syn:- metrical armature sections rotating in a sint'gh e magnetic field and separately connected to t e individually sprung driving wheels It. By :1 rtue of such a construction independent rota on of the driving wheels is permitted, thereby giving the advantages of a conventional differential without actual use thereof. In addition, mounting of the motor I! on the vehicle strucat-1 ture instead of rear axle and the individuht wheel suspension decreases the unsprung weig of the body, thus giving an additional advantage. The wheel and the motor suspensions do not form a part of the present invention, ang therefore no detail description thereof is deeme erein.

if gegtrical connection of the sections II and ll of the storage battery with the electric motor includes a control device "provided within convenient reach of the operator s foot. The device II is operated with the aid of a foot peda 2| hingedly connected to the bar 2; actuating the device. All of the cells of the sections i and H are connected by means of separate conductors to the control device 20, said conductors in athered into two cables II and N, while El m :or itrol device I. is connected with the electric motor I! by means of a two-conductor cable It. A three-conductor cable 2| connects a switch 21 provided on the instrument panel of the vehicle with the control device, said switch perbattery only but evenly from all cells of the battery. To perform the above functions, the electric control device may be constructed as in the present embodiment of the invention which is illustrated in Figs. 2 and "I inclusive.

Referring to the drawings, the control device comprises a plurality of outer contact pieces or segments 21 and a plurality of inner contact pieces or segments 28, said segments being circularly arranged in pairs and insulated from each other, the number of segments of each kind corresponding to the number of cells in the battery. All the cells of the battery are connected to the control device in such a manner that each positive terminal of every individual cell is connected to one outer segment 21, while the negative terminal of the same cell is connected to the inner contact segment 28 of the same pair of segments, it being understood that the inner and the outer segments are arranged in pairs. Each of the outer contact segments of one pair is connected with the negative contact segment of the adjacent pair and, therefore, a series connection of the cells is produced. It will be understood that it is possible to provide a group of cells connected in parallel in the usual manner and then have the groups of such parallelly connected cells connected in series with the aid .of the control device of the present invention.

Therefore, in the wiring diagram of Fig; 7, one

. cell may be taken as representing a single cell mitting breaking the motor circuit for stopping losin the circuit for starting the mg rr i d reversin g the direction of the current through the circuit, thereby reversing the direction of rotation of the motor for backward movement of the vehicle.

The electrical control device provided in acrdance with the present invention is adapted establish and maintain electrical connections between a desired number of the battery cells and the electric motor. In the present embodiment the control device is so arranged that as the ,foot pedal 2| is pressed down further and further, a gradually increasing number of battery cells becomes connected to the electric motor It. With the foot pedal pressed all the way down, all the cells are connected to the electric motor and the same delivers its maximum power. Another important feature of the present invention resides in the fact that when the pressure on the foot pedal is released the same returns to its original position disconnecting thev cells from the motor. When the foot pedal II is pressed downagain after being released, the control device operates to connect to the electric motor the cells which remained inactive during the previous application of the foot pedal. By virtue of the above described construction the motor vehicle can be accelerated to its maximum speed by the application of the foot pedal only. without shifting gears and performing other operations indispensable with the vehicle employing internal combustion engines. At the same time when driving, working of the foot pedal up and down, invariably occurring in actual driving, operates to alternate the cells and to draw as well as a groupof cells correspondingly connected. Two rotating contact arms, a positive contact arm 2| and a negative contact arm ll, are adapted to slide over respective contacts and to provide electrical connections with the conductors Ila and 25b of the motor cable 2! connecting the same with the desired number of electric cells. The positive arm 19 carries a pin ll adapted to open the interrupter switch 82 which connects the positive segment with which the arm a is in contact at the moment, and the negative contact segment II,

From an examination of the wiring diagram of Fig. 7 it can be clearly seen that with the connections shown in said diagram the current will flow from the positive terminal of the cell an to the positive contact segment 21. Since the pin 3| keeps the interrupter switch 32 open, the flow of current to the negative contact segment 28 is prevented, and the current flows through the body of the positive contact arm 2! and a conductor "a to the motor 12, it being understood that the arms I! and 30 are electrically insulated from each other. From the motor I! the current flows through the conductor Ilb to the negative contact arm 30, negative contact segment 28b, conductor II to the negative terminal of' the cell "17. Since the positive terminal of the cell lib is connected to the positive contact segment of the adjacent pair of segments which positive segment is connected by means of the interrupter switch with the negative segment of the next adjacent pair of segments, and the latter is connected with the negative segment of the next cell, a flow of current from cell to cell through the contact segments from the cell "b to the cell "a is uninterrupted. Thus, all the cells between and including the cells Ila and lib are connected and feed the current into the motor l2. At the same time, it will be the electric current not from one portion of h noticed that there cannot be any new of electric current between the cell Nb and the cell "c,

since there is no electrical connection between the negative contact segment Nb and the neganected M mi's somewhere same when the barrfl. is pushed down. 'Ihe' rack tive terminal" of ii to. In" other words,

. only cells are includedbet'ween the contactiarms'1llahdll are connected to the motorfllhe widerj 2! and; "are spread,v the larger is the number of cells connected to the motor. If both arms I! and I bear on therespe'ctive contact segments of a single of segments, practically no flow of current through the motor takes place.

- In accordance withthe present invention means are-provided to spread the, II and in respouse to the pressure on the pedal II. As

shows in I'l'gs. 2 and 3, the contact segments I1 and ll are mountedon an insulated round plate II ati'the-'icenter'iof which'the is*provided a shaftll,,; on which rotaticn ftnerewith. ratchet curely mounted on the shaft II. On the same shaft .Ewthflg isJrotatablyimounted a sleeve rotatable independently of saidshaft, on which sleeve therearehseourely moimted the positive contact arm 'iland' second ratclit wheel 38.

1m 1 some con inden i g n To'the lI id. U, ,V

iadapted 1 to rotate the I is dapted to mother -to et heel 1: a d to rotate" the'same when the; bar llmoves upward. ,It shouldbe noted because of the proreturn to its original position but remains in the position into which itwas moved by the application of the foot pedal, the decrease in the flow of current to the electric motor I! being achieved by causing the negative contact arm ill to move toward the positive contact arm. and to contact the negative segment of the pair of segments,- the positive segment of which is contacted at the moment by the positive contact arm 2!. It can be clearly seen from an examination of the drawings that when the bar 22 moves upward (to the right in Fig. 2), the ratchet wheel ll connected to. the positive contact remains stationary,

since the teeth of the rack It, because of their direction, ride over the teeth of said ratchet wheel II. On the other hand, the rackll in its upward motion rotates the ratchet wheel 31 moving the negative contact arm 38 in the counterclockwise direction. Since the return stroke 'of the bar 22 -must be equal to the prior downward stroke thereof, the negative contact arm 3| will be rotated through the same angle and therefore it will come into the position to contact the negative segment of that pair of contacts, the positive "segment oi which is in contact at the moment with the positive arm rs. In the succeeding ap-v plication of the foot pedal, the positive arm 2! will be moved forward over the remaining contact segments and therefore the current will be drawn not from the cells which were connected to the motor in the prior application of the foot pedal but to the cells which remainedinactive during said application. By virtue ofsuch a convision'of'a doe tflotn'ivneeis 'can rotate only in the pedal ll is pushed down, the rack 40 engages the wheel a and rotates the same in the. counterclockwise direction moving the positive contact arm 20 over a number of positive contact segments, thereby connecting the cells connected to the contact segments included between the negative contact arm 0! and the positive contact I! to the motor II. The further the pedal II is pushed down, the greater is the number of cells connected to the motor. The operative stroke of the pedal II- is so selected that when said pedal is pushed all the way down, the positive contact arm makes a practically complet revolution and contacts the positive contact segment adjacent or nearly adjacent tothe pair of contactsegments, the negative segment of which is in contact with the negative-contact arm}... As-the rack moves downward (to the left mm. 2) the rack "also. moves downward but since the teeth on said rack 4i are'cut in the opposite direction to the teeth on the rack 40.

the rack Ill simply'rides over the ratchet wheel 31 without producing any rotation thereof. any

tendency of rotation of the wheel 31 being resisted by the do: II. I

An important advantage of the present invention results from the fact that as the pedal,

2|.is released and returns'to its original position because of the pressure exerted thereon by a spring 44, the positive contact arm It does not' struction the current is drawn evenly from all cells of the battery and the same is evenly discharged. The above is an important advantage of the present invention since drawing current from the first few cells on every application of the foot pedal and at the same time leaving other cells inactive under average driving conditions produces a very objectionable uneven discharge of the battery and ineflicient use thereof. It will require a much larger battery for the same performance of the motor vehicle than it is possible'to use in connection with a motor vehicle constructed in accordance with the presentv inv vention. a

posed of a plurality of electric cells, an electric The construction of. the interrupter switch 32 is shown in detail in Fi 6 and the operation of said switch is clear from anexamination of said flgurein the light of the prior'description.

I claim: I

1. In an electric motor vehicle, a battery commotor, a control device including a plurality of pairs of contact pieces, each pair including a positive and a negative contact connected to'the positive and to the negative terminal of a respective=cell, a plurality of interrupter switches normally connecting the. positive contact of one pair of contacts to'the negative contact of the adjacent pair, whereby all of the cells are con nected in series, two movable contact arms electrically connected to said motor, one of said arms adapted to make successive contacts with the positive contact pieces and the other with the negative contact pieces, and means operable by one of said arms, said means being adapted to i open the interrupter switch connecting the contact piece on which said arm bears with the piece of the adjacent pair, whereby only the cells connected to the contact pieces included between-said arms are connected to the motor.

2. In an electric motor vehicle, a battery composed of a plurality of electric cells, an electric motor, a control device including a plurality of pairs of contact pieces, each pair including a positive and a negative contact connected to the positive and to the negative terminal of a respective cell, a plurality of interrupter switches normally connecting the positive contact of one pair of contacts to the negative contact of the adjacent pair, whereby all of the cells are connected in series, two movable contact arms electrically connected to said motor, one of said arms adapted to make successive contacts with the positive contact pieces and the other with the negative contact pieces, a member carried by one of the arms and adapted to open the interrupter switch connecting the contact piece upon which said arms bear at the moment with the contact piece of the adjacent pair.

3. In an electric motor vehicle, a battery composed of a plurality of electric cells, an electric motor, a control device including a plurality of pairs of contact pieces, each pair including a positive and a negative contact connected to the positive and to the negative terminal of a respective cell, a plurality of interrupter switches normally connecting the positive contact of one pair of contacts to the negative contact of the adjacent pair, whereby all of the cells are connected in series, two movable contact arms electrically connected to said motor, one 01' said arms adapted to make successive contacts with the positive contact pieces and the other with the negative con tact pieces, a member carried by one of the arms and adapted to open the interrupter switch connecting the contact piece upon which said arms bear at the moment with the contact piece of the adjacent pair, and pedal controlled means for operating said control device.

4. In an electric motor vehicle, a battery composed of a plurality of electric cells, an electric motor, a control device including a plurality of pairs of contact pieces, each pair including a positive and a negative contact connected to the positive and to the negative terminal of a respective cell, a plurality of interrupter switches normally connecting the positive contact of one pair of contacts to the negative contact of the adjacent pair, whereby all of the cells are connected in series, two movable contact arms electrically connected to said motor, one of said arms adapted to make successive contacts with the positive contact pieces and the other with the negative contact pieces, a member carried by one of the arms and adapted to open the interrupter switch connecting the contact piece upon which said arms bear at the moment with the contact piece of the adjacent pair, and means whereby said arms are moved'in one direction.

5. In an electric motor vehicle, a battery composed of a plurality of electric cells, an electric motor, a control device including a plurality of pairs of contact pieces, each pair including a positive and a negative contact connected to the positive and to the negative terminal of a respective cell, a plurality of interrupter switches normally connecting the positive contact of one pair of contacts to the negative contact of the adjacent pair, whereby all of the cells are connected in series, two movable contact arms electrically connected to said motor, one of said arms adapted to make successive contacts with the positive contact pieces and the other with the negative contact pieces, a member carried by one of the arms and adapted to open the interrupter switch connecting the contact piece upon which said arms bear at the moment with the contact piece of'the adjacent pair, a foot pedal for moving one of said contact arms through a desirable number of contact pieces to connect the corresponding number of cells to said motor, and means bringing the second of said arms to the first arm when said pedal is released.

6. In an electric motor vehicle, a battery composed of a plurality of electric cells; an electric motor; a control device comprising a corresponding plurality of positive contact segments circularly arranged and connected to the positive terminals of the cells, respectively, a corresponding plurality of negative contact segments connected to the negative terminals of said cells, respectively, arranged circularly and in pairs with said positive segments, a corresponding plurality of interrupter switches connecting the adjacent pairs of segments in series, two movable contact arms electrically connected to the positive and the negative terminals or said motor, respectively, and adapted to contact said segments to connect a desirable number of cells to said motor, and means adapted to operate said interrupter switches to open the switch on which one of said arms bears at a particular moment.

7. In an electric motor vehicle, a battery composed of a plurality of electric cells; an electric motor; a control device comprising a corresponding plurality of positive contact segments circularly arranged and connected to the positive terminals of the cells, respectively, a corresponding plurality of negative contact segments connected to the negative terminals of said cells, respectively, arranged circularly and in pairs with said positive segments, a corresponding pluralityoi' interrupter switches connecting the adjacent pairs of segments in series, two movable contact arms electrically connected to the positive and the negative terminals of said motor, respectively, and adapted to move around over said segments to establish electric contact therewith, and means carried by one of said arms and adapted to open the interrupter switch connecting the contact segment on which said arm bears with the segment of the adjacent pair to connect the cells included between said arms to said motor.

8. In an electric motor vehicle, a battery composed of a plurality of electric cells; an electric motor; a control device comprising a correspondingplurality of positive contact segments circularly arranged and connected to the positive terminals of the cells, respectively, a corresponding plurality of negative contact segments connected to the negative terminals of said cells, respectively, arranged circularly and in pairs with said positive segments, a corresponding plurality of interrupter switches connecting the adjacent pairs of segments in series, two movable contact arms electrically connected to the positive and the negative terminals of said motor, respectively, and adapted to move around over said segments to establish electric contact therewith, means carried by one of said arms and adapted to open the interrupter switch connecting the contact segment on which said arm bears with the segment of the adjacent pair to connect the cells included between said arms to said motor, a foot pedal for moving one of said arms forward over a number'of segments when the pedal is pressed, and means retaining said first arm at the place reached to bring the second arm thereto when the pedal is released.

JOHN TJAARDA. 

